Aqueous organopolysiloxane emulsions have been used heretofore as release agents, as lubricants, or for rendering organic and mineral substrates hydrophobic and as textile finishing agents. In these applications, the aqueous emulsions are in contact with iron or nonferrous heavy metals which are susceptible to corrosion.
It is known that sodium nitrite, organic amines or inhibitors based on sodium benzoates can be added to aqueous organopolysiloxane emulsions to reduce corrosion. When sodium nitrite is added to the aqueous organopolysiloxane emulsions, nitrosamines often form on addition of tertiary amines. This frequently occurs because the polysiloxane emulsions are often combined with other aqueous compositions. Moreover, the addition of organic amines or salts of benzoic acid and derivatives thereof often contributes to the destabilization of the composition, and thereby reduces the effectiveness of the composition after application. Furthermore, organic amines form colored complexes with many metal ions, thereby making the compositions less desirable because of their optical appearance.
Therefore, it is an object of the present invention to provide aqueous organopolysiloxane emulsions which are noncorrosive. Another object of the present invention is to provide aqueous organopolysiloxane emulsions which do not form nitrosamines. Still another object of the present invention is to provide aqueous organopolysiloxane emulsions which have better stability. A further object of the present invention is to provide aqueous organopolysiloxane emulsions which do not interfere with the application. A still further object of the present invention is to provide an aqueous organopolysiloxane emulsion which does not discolor in the presence of metal ions and accordingly provide emulsions having a desirable optical appearance.